Gut mucosal surfaces bear many receptors, sensitive to nutrients and other signaling molecules that reflect changing conditions in the environment of the gut. Modulation of these receptors can have effects ranging from local (modulating intestinal inflammation) or intuitive (modulating hunger and satiety) to systemic (diabetes) or neurological (depression). However, many compounds that effectively modulate these receptors to beneficial effect in the gut cause adverse effects when these compounds are absorbed and affect receptors elsewhere in the body. Improved methods for selectively targeting gut receptors are needed.